The present invention relates to an electric shaver which drives inner blades set inside of outer blades with reciprocating motion.
FIG. 1 and FIG. 2 are exploded perspective views showing a known electric shaver having inner blades which are movable with a reciprocating motion. In the electric shaver shown in FIGS. 1-2, inner blades 130 are connected to up-down rods 131 of inner blade stages 128, respectively. The inner blade stages 128 are mounted in blade support 132 to allow reciprocating motion via flexible arms 134 mounted at both ends of the plate 135 which supports inner blade stage 128. The blade support 132 is mounted to the outer blade frame 107 in a removable manner, then mounted to a shaver body 127 via the outer blade frame 107. When the inner blade stages 128 are mounted to the shaver body 127, the inner blade stages 128, which are connected to vibrator stages 117, housed-in the shaver body 127, move with reciprocating motion. That is to say, in the electric shaver having this structure, a motor 118 drives the vibrators 117 in reciprocating motion, the vibrators 117 drive the inner blade stages 128 in reciprocating motion, and the inner blade stages 18 drive the inner blades 130 in reciprocating motion. Namely, the vibrators 117 driven in reciprocating motion by the motor 118, drive the inner blades 130 in reciprocating motion via the inner blade stages 128.
The inner blades 130 need to be driven in reciprocating motion while being flexibly pressed against the inner face of the outer blade 129. It is necessary to ensure that the beard, which protrudes from beard cutting ports of the outer blade 129 into the inside, is cut by the reciprocating inner blades 130. In order to have the inner blades 130 move in the reciprocating motion along the inner face of the outer blades 129, each of the inner blade stages 128 comprises up-down rod 131. As shown in an exploded oblique view of FIG. 3, the up-down rods 131 are flexibly pushed upwards by built-in pressure springs 133. The pressure springs 133 are housed-in the up-down rods 131, and push the up-down rods 131 upward flexibly.
According to the present description, the up-down direction is determined by the vertical posture of the electric shaver as shown in FIG. 1.
Turning to FIG. 4, in order to connect the up-down rods 131 to the inner blades 130, the inner surface of inner blade supports 130A is configured to connect to the up-down rods 131. The inner blades 130, shown in an oblique view of FIG. 4, are integrally formed with connecting support struts 130B at the inner face of the inner blade supports 130A which are made of plastic. Since the connecting support strut 130B is inserted into the inside of the up-down rod 131, the connecting support struts 130B are designed with an external width which has substantially the same width as the internal side of the up-down rods 131.
Furthermore, each of the inner blade supports 130A has a pair of locking parts 130C formed at the inner face and protruding inside to prevent them from coming off the up-down rods 131. The locking parts 130C are positioned at the center of the inner blade support 130A, which has parallel plates to each other, and integrally formed at the lower edge. The locking parts 130C are guided into latching windows 131A formed in the up-down rods 131 when the inner blade 130 connects the up-down rods 131 so as to prevent the inner blade 130 from coming off the up-down rod 131. When the connecting support struts 130B of the inner blades 130 are inserted into the up-down rod 131 to connect them, the inner blade supports 130A, which have the shape of parallel plates, flexibly open the width between these parallel plates widely and the locking parts 130C are guided into the latching windows 131A of the up-down rods 131. After the locking parts 130C are guided into the locking windows 131A, then the width of the plates of the inner blade support 130A tend to recover its narrow width, and the locking parts 130C latch into the latching windows 131A.
As shown in FIGS. 4 and 5, each of inner blade stages 128 has driving pin 128A which protrudes downwards at the bottom thereof to connect with the vibrator of the shaver body. Each of the driving pins 128A is introduced into axis port 117a, provided at the center of the vibrator 117 as shown in FIG. 2, with no gap to connect to the vibrator 117. The axis port is configured with a tapered shape with a wider upper portion whereby the driving pin 128A is guided at the center portion.
The electric shaver with the above-mentioned structure mounts the inner blades so as to connect to the up-down rods of the inner blade stages in order that these inner blades are driven in an up-down motion by the up-down rods. The electric shaver of this structure needs to connect the inner blades to the vibrator via two parts, the up-down rod and the inner blade stage. Consequently the clearance between the inner blade and the up-down rod, the up-down rod and the inner blade stage, and the inner blade stage and the vibrator act to reduce the stroke driving the inner blades in reciprocating motion, and also cause disagreeable noise or shaking.
Further, with this structure, numerous parts are needed, and the structure connecting the inner blades to the vibrators becomes more complicated. In addition, if the quality of each manufactured part is low, then the clearance occurs and the above mentioned problems will happen. This is why a high level of quality of manufacturing each part is required, and this will cause a rise in production costs, or the assembly process takes more time, namely, the manufacturing cost is greater.
Furthermore, because the electric shaver of this structure moves the up-down rod with vertical strokes, there is another drawback in that it is difficult to augment the stroke span of the up-down rod. Further, if the stroke of the up-down rod is augmented, this part becomes higher and the overall length of the electric shaver becomes greater, and as a drawback, compactness cannot be maintained.
The present invention has been developed with the object to solve these drawbacks. The first object of the present invention is to offer an electric shaver with a simplified driving mechanism which drives the inner blades in reciprocating motion, allowing a lower price for mass production, and also reducing the noise and the shaking problem of the mechanism which drives the inner blades in reciprocating motion.
Then, the other important object of the present invention is to offer an electric shaver which makes it possible to augment the stroke of the inner blades via a simplified mechanism.
By the way, the prior art electric shaver connects the inner blades 130 to the shaver body 127 via the inner blade stages 128 and the blade support 132, and the outer blades 129 to the outer blade frame 107 an outer blade case 106 in a removable fashion. According to this electric shaver, when the outer blade case 106 is removed from the outer blade frame 107, the inner blades 130 remain on the inner blade stages 128 of the blade support 132 of the outer blade frame 107. For this reason, the outer blades 129 and the inner blades 130 cannot be removed together and therefore washed cleanly by immersion into a cleansing liquid such as a bubbling liquid or the like. On this account, in order to clean these parts by immersion into a cleansing liquid, it is necessary to remove the outer blade case 106 from the outer blade frame 107, and then remove the inner blades 130 from the inner blade stage 128. Therefore, this is a drawback because the cleaning procedure takes a significant amount of time.
In addition, it could happen that the inner blades 130, which are of a small size, can be dropped and lost when removed and then immersed into a cleansing liquid, or when cleaned by hand. Further, after the outer blade case 106 is removed, a safe cleaning of the metallic blades cannot be achieved because the inner blades 130 with numerous fairly thin metal blades are exposed. Furthermore, there is another drawback in that the thin metal sheets can be easily deformed and damaged.
The present invention has been further developed with the object to solve these drawbacks. The second important object of the present invention is to provide an electric shaver which will allow the inner blades to be connected to the outer blades with a fairly simplified structure, and thus permit easy and safe cleaning of both the inner blades and the outer blades at the same time.
Another important object of the present invention is to offer an electric shaver with inner blades which can be cleaned without being deformed and damaged.
The above and further objects and features of the invention will more fully be apparent from the following detailed description and accompanying drawings.